Structures such as a rectangular building and utility posts typically present significant impediments to surrounding flow of air. Impediments to flow of air can cause various disturbances to the flow such as creation of vortices and turbulence. In general, such structures are classified as bluff bodies.
A bluff body is a body having a shape that, when immersed in a fluid flow, causes separation of the flow over a substantial part of its surface. Such separation of flow typically results in turbulence, and creates a turbulent wake in the downstream region. Aerodynamic forces experienced by a bluff body are typically dominated by pressure drag, or form drag, as opposed to viscous drag which is the dominant force experienced by a streamlined body.
An anemometer is a measuring device for measuring speed and/or direction of gas flow, such as air. Anemometers are commonly used to measure wind speed, for example.
A plasma actuator is a plasma generating device for imparting a net momentum transfer to the surrounding fluid through the generated plasma. The plasma may be generated, for example, through dielectric barrier discharge (DBD), corona discharge, or glow discharge.